Method of making deoxidized copper and copper alloys



Patented June 4, 1935 UNITED STATES PATENT OFFICE METHOD OF MAKINGDEOXIDIZED COPPER AND COPPER ALLOYS No Drawing.

50 Claims.

This invention relates to the manufacture and treatment of copper to beused in various forms, and to copper alloys and method of making them,and has for an object the production of deoxidized copper and improvedcopper alloys and an improved method whereby such deoxidized copper andimproved alloys may be readily produced in large quantities and withuniformity in the mill.

It is also an object of the invention to provide an improved method ofdeoxidizing copper to be used in various forms such as electricalconductor wire, bars, and so forth, to secure a conductor of highelectrical conductivity and which is able to withstand repeated bendingwithout breaking after being annealed in hydrogen.

Another object of the invention is to provide a method of deoxidizingcopper whereby a uniform product may be produced commercially and onehaving definite characteristics which may be secured with certainty.

This application is in part a continuation of each of our priorapplications Serial No. 616,096 filed June 8, 1932 for Method of makingdeoxidized copper, and Serial No. 690,764 filed September 23, 1933 forMethod of making deox-' idized copper.

The improved method of making the copper alloys consists broadly infirst the removal of the greater proportion of the gases in the copperwhich readily come out, that is, give the gases an opportunity toescape, to then completely deoxidize the copper with a deoxidizer whichdoes not form a reaction product which is gaseous at room temperatureupon combining with the oxygen of the copper, and then adding one ormore alloying elements. The deoxidizer is preferably used in amounts inexcess of that required to completely deoxidize the copper so that thereis an excess or a residual amount of the deoxidizer in the copper whenthe alloying element or elements is or are added, and this deoxidizermay form one of the elements of the alloy produced.

There are several different methods of procedure by .which the coppermay be treated. Broadly, as disclosed in our prior application SerialNumber 690,764 above mentioned the copper is melted in a suitablecontainer and brought to an oxygen content of not more than 0.090percent, preferably considerably less than this, probably never over0.040 percent, and generally less than 0.025 percent, by treatment withcarbonaceous or other reducing materials, then allowing the greaterproportion of the gases to melted copper treated with carbonaceous orother escape, and then the copper is completely de- Application October20, v1933, Serial No. 694,522

oxidized by the addition of a deoxidizing agent which does not form areaction product which is gaseous at room temperature upon combiningwith the oxygen of the copper and therefore will prevent swelling of thecopper on freezing. The 5 final deoxidizer may or may not be a metallicdeoxidizer depending upon for what the copper is to be used or upon thealloy it is desired to produce, and when the copper is to be used foralloys the deoxidizer is preferably added in sufficient amount so thatthere is a residual amount of the deoxidizer remaining in the copperwhen the alloying element or elements are added. That is, it ispreferred that somewhat more of the deoxidizer be added than is requiredmerely 15 to deoxidize the copper to insure that the copper iscompletely deoxidized, and furthermore, this excess of deoxidizer may beone of the alloying elements of the finished alloy. It is, however, notnecessary that the final deoxidizer be used in 0 excess of that requiredto deoxidize the copper, as we have deyeloped methods of deoxidizing thecopper whereby very little, if any, final deoxidizer remains in thecopper.

The procedure in our method of making de- 5 oxidized copper and copperalloys may vary considerably. Thus, for example, the copper when meltedin the container may be melted under any type of cover or under no coverat all and the reducing material until practically deoxidized. 0

We prefer to use charcoal as this reducing material and may melt thecopper under a layer of this charcoal until the proper temperature issecured, which we estimate to be in the neighborhood of 1200 C., or ifpreferred the charcoal may be stirred into the melted copper. At thistime the copper containsgases. If the copper has been melted underreducing conditions as for example under a layer of charcoal, if oxygenis present 40 it is only in minute amounts. If the copper is treated bystirring carbonaceous material into it we prefer to use partially burnedor calcined charcoal or other carbonaceous material similar incomposition to said partially burned or calcined charcoal. The charcoalwhich has been used as a cover in melting down the copper is verysatisfactory for this purpose. The copperis then exposed to oxidizingconditions, preferably to the air, to permit the gases to get out. Thesegases. apparently are those which readily react with the air when theycome in contact with it and other gases which may be in the metal andescape when the metal is exposed, and during this time the copper may ormay not be stirred with a graphite rod'or any suitable type of rod. Itis not necessary to this process that all of the gases escape,

but it is preferred that the larger proportion of them do so, or thatthose that come out readily be permitted to do so. During this exposureof the copper to the air or other oxidizing conditions there is comeoxidation of the copper, but it never exceeds 0.090 percent and it isgenerally considerably less than this, probably never over 0.040 percentand generally less than 0.025 percent. The copper may then be coveredwith carbonaceous material to prevent further oxidation if desired, butthis, however, is not necessary unless possibly the copper is to beexposed for an unusual length of time.

The copper is then deoxidized with non-carbonaceous material which iscapable of preventing the swelling of the copper on freezing. That is,the copper is deoxidized with the addition of a deoxidizing agent oragents which does not form a reaction product which is gaseous at roomtemperature upon combining with the oxygen of the copper. We prefer touse a metallic deoxidizer for this purpose although we are notnecessarily limited thereto. Thus for example we may use aluminum,manganese, lithium, calcium, or other suitable metallic deoxidizers, orwe may use suitable non-metallic deoxidizers, such for example as boron,silicon, or phosphorus, or we may use such deoxidizers as metallicbprides, metallic silicides, metallic phosphides or other suitabledeoxidizers. In making alloys we preferably add sufiicient of thedeoxidizer so that there is a residual amount of this deoxidizerremaining in the finished metal. This insures that the copper iscompletely deoxidized, and more or less of the deoxidizer may bedesirable in the finished metal. Thus, for example, in making aphosphor-bronze, phosphorus may be used as the final deoxidizer and inamount not only sufficient to deoxidize the copper but a sufficientexcess is used to provide the amount of phosphorus desired in thefinished phosphor-bronze alloy. Then the desired amount of tin isadded-to complete the alloy.

The amount of deoxidizer required to complete the deoxidation of thecopper may be determined by taking samples of the copper and addingdeoxidizer until the metal does not swell on freezing and then addingsufiicient surplus to insure that there is some residual deoxidizer inthe finished copper. As the oxygen content never goes over 0.090 percentand generally is much less than this, for a given weight of copper theamount of deoxidizer required to insure complete deoxidation can bereadily determined. If borides and similar deoxidizers are used theremay not be any of the deoxidizer remaining in the alloy after casting.We may use one metallic or non-metallic deoxidizer for deoxidizing thecopper, such for example as aluminum, manganese, calcium, boron,silicon, and phosphorus, or we may use two or more of the deoxidizers ifit is so desired.

The deoxidizer may be added as a free element or if a more fine controlis desired it may be added in the form of an alloy with copper. Thus forexample if aluminum isthe deoxidizer it may be added as a metallicaluminum in small pieces or it may be added as a copper aluminum alloy.Such alloy may contain '75 percent copper and 25 percent aluminum, orany other known or suitable proportion may be used without afiecting theprinciple of operation. As stated above we may use combinations of twoor more different deoxidizers. Thus, for example we may partiallydeoxidize copper with the aluminum or another metal and then completethe deoxidation by the addition of a different and another metal, suchfor example as manganese where the first metal is aluminum. The secondmetal may be added either as free metal or as an alloy with copper.

After the copper is deoxidized with the final deoxidizer an alloyelement or elements is or are added to produce the desired alloy. These,for example, may be such elements as cadmium, tin, zinc, aluminum,nickel, or any other suitable element or combination of elements toproduce such alloys as for example phosphor-bronze, cadmiumbronze,nickel-silver, cupro-nickel, brass, or any other copper alloy. The alloymay then be poured into suitable molds and may be used for the purposeintended.

A slightly modified procedure is to melt the copper in a suitablecontainer under oxidizing conditions. The copper is then treated withcarbonaceous or other reducing materials, such for example as thecalcined or partially burned charcoal, until the oxygen content isreduced to 0.090 per cent or less. Crdinarily it would be much less thanthis amount. The copper is then exposed to oxidizing conditions to allowthe greater proportion of the gases to escape. Then the metal isdeoxidized with non-carbonaceous material by adding predeterminedamounts of me tallic or other deoxidizers capable of preventing swellingof the metal on freezing, that is by use of deoxidizers which do notform a reaction product which is gaseous at room temperature uponcombining with the oxygen of the copper. If

metallic deoxidizers or 'such non-metallic deoxidizers as phosphorus orsilicon are used they may be added in sufficient amount to produce aresid- V ual amount of deoxidizer in the copper as indicated above. Ifborides and similar deoxidizers are used there may not be any of thedeoxidizer remaining in the copper after deoxidizing. In other words thecopper is finally deoxidized after treating with carbonaceous or otherreducing materials to bring it to an oxygen content of less than 0.090per cent in the same manner as is indicated in the first procedure. Ifan alloy is desired then one or more alloying elements are added in theproper amounts to produce the alloy desired. The metal may then be castand worked asdesired.

Another somewhat modified procedure is to melt the copper in a suitablecontainer under any type of cover or under no cover at all. The moltencopper is then poured into a ladle or other suitable and portablecontainer which may or may not have a source of heat for raising ormaintaining the temperature of the copper therein. Such containers maybe in the form of electric furnaces, gas fired furnaces, or oil firedfurnaces. When a furnace is substituted for a ladle in this operation weprefer some form of an electric furnace. The melted copper is thentreated with carbonaceous or other reducing material until substantiallydeoxidized. We prefer to use partially burned or calcined charcoal. Thecopper is then exposed to the air to permit the larger proportion of thegases to escape, and there is some oxidation of the copper, but never toan oxygen content of over 0.090 percent and ordinarily much less thanthis as indicated in the first procedure described above. The coppermay.-

on freezing. As indicated "above the deoxidizer used preferably is addedin sufiicient amount to produce a residual deoxidizer in the copper. Ifborides or similar deoxidizers are used there may not be any deoxidizerremaining in the copper. One or more alloying elements are thenadded tothe copper to produce the alloy desired. This alloy may then be cast andworked as desired.

Still another somewhat modified procedure may be used in which thecopper is melted in a suitable container under oxidizing conditions. Themolten copper is poured into a ladle or other suitable and portablecontainer, which may or may not have a source of heat for raising ormaintaining the temperature of the copper there- .in. Such container maybe in the form of an electric furnace, gas fired furnace, or oil firedfurnace. When a furnace is substituted'for a ladle in this operation weprefer someform of an electric furnace. The melted coper is then treatedwith carbonaceous or other reducing materials until the oxygen contentin the copper is reduced to not more than 0.090 percent and preferablyconsiderably less than this as above indicated, and then exposed tooxidizing conditions to allow the larger proportion of the gases toescape. The copper is then finally deoxidized by non-carbonaceousmaterials, such as metallic or other deoxidlzers capable of preventingswelling of the metal on' freezing as described in connection with theother procedures as above noted, and preferably with a surplus ofdeoxidizer so that there is a residual amount of deoxidizer in thecopper, and then one or more alloying elements are added to produce thealloy desired.

It will be noted from the above that we can reduce the oxygen content ofmelted copper to 0.090 percent or less with /suita';ile reducing agents,particularly carbonaceous material, such as charcoal, and canproduce-completely deoxidized copper.before adding the alloying elementor elements by treating the copper from this point with non-carbonaceousmaterial which does not form a gaseous reaction product upon combiningwith the oxygen of the copper and is therefore capable of preventingswelling of the metal on freezing. After the metal has been treated withthe carbonaceous material theoxygen content is never more than 0.090percent and is ordinarily much less than this, probably never over 0.040percent, and the indications are it is less than 0.025 per cent.

It has not been generally realized that the melted copper is saturatedwith gases, probably some combustible and some non-combustible, and wehave found that if these are allowed to escape and the oxygen content isnot over 0.090 percent, although preferably much less than this amount,then the final deoxidizer added, and then the alloying element orelements added much better alloys and castings of these alloys which arepreferably sound can be obtained. With a little testing we can soon findout how much of the final deoxidizer to add under given conditions so as.to secure aresidual amount of the deoxidizer in the copper and stilldeox'idize it. We have discovered that there is never an oxygen contentof over 0.090 percent when the gases have been allowed to escape, and asa matter of fact ordinarily much less than this. With a little practiceone can tell from the general appearance of the copper when the gaseshave escaped sufficiently from the metal to permit adding the finaldeoxidizer safely, one indication being that the absence of a finecopper spray is very noticeable. Also that the molten copper graduallytakes on a bluish or greenish cast and boils quite violently.

Where a more accurate control of the final deoxidizer and a moreaccurate and uniform control of the characteristics of the metal isdesired we use a somewhat different procedure, as

disclosed in our prior application Serial Number 616,096, abovementioned.

It has been difficult to produce deoxidizedcopper with a high electricalconductivity and which will stand the desired amount of bending withoutbreaking, after annealing in hydrogen, and especially it has beendiflicult to secure a uniform product. We have discovered a method ofdeoxidizing copper by which we can secure an electrical conductivity ofat least 99.5 per cent at 20 C. in terms of the International AnnealedCopper Standard, and it can also withstand a minimum of ten bends aftera thirty minute anneal in a hydrogen atmosphere at 850 0. Furthermore wecan produce this copper on a commercial scale and with a uniformitywhich will maintain at least these standards. In the bending test thecopper is bent around a radius 2.5 times the thickness or diameter ofthe copper rod, wire, or whatever the shape happens to be, the copperbeing first bent 90. in one direction and then back to the original.position. This constitutes one bend. The second bend is in the oppositedirection around the same radius 90 and then back to the originalposition. The third bend is the same as the first, and so on.

Metals have been used for many years to deoxidize copper but neverbefore has such a c pper passed the above tests. In order for the copperto pass such tests there must be only m nute amounts of the deoxidizerremaining in the finished copper, as only small amounts will materiallyreduce the electrical-conductivity of the copper. On the other hand ifsufficient amounts of the deoxidizer are not added to the copper tocompletely deoxidize it then the copper can not withstand the bendingtest as above noted. It willbe' evident that as it is difllcult todetermine under ordinary operations the exact amount of the oxygen inthe copper and therefore to determine th exact amount of deoxidizerreouired to completely d oxidize the copper and still not have a surplusof the deoxidizer to remain in the copper and decrease the electricalconductivity, it was practically impossible to produce deoxidized coppercommercially which could meet the above standards.

We have discovered that with certain treatments of the copper we canbring it to a definite end point or condition where it has a definiteoxygen content. and we therefore know the exact amount of deoxidizerwhich should be added to completely deoxidize the copper and still havea m nimum amount of deoxidizer remain in the copper, and we can keep thecontent of the deoxidizer sufficiently low so that the electricalconductivity is 99.5 per cent or higher at 20 C. in terms of theInternational Annealed Copper Standard.

In carrying out this method or procedure the copper may first be meltedin any suitable furnace but, we prefer a high frequency electric furnaceas in such a furnace the operation may be more easily controlled. Thecopper is preferably melted under a cover of charcoal but other coversmay be used and in fact it may be melted tion of a definite oxygencontent.

this gives us less work and more definite control in another part of themethod.

When the copper is melted and the proper temperature attained which weestimate to be in the neighborhood of 1200 C. the charcoal or othercover is removed. The copper at this point contains gas, and if oxygenis present it is only in minute amounts. The copper is agitated with asuitable stir rod such for example as graphite, or it may be agitatedwith a'furnace current, un-'- til it shows a boiling action. This actiontends to throw off the gases in the copper and particularly the easilycombustible gases or those which readily react with the air when theycome in contact with it. This boiling action of the copper exposed tothe air also causes some oxidation of the copper. After the copper hasboiled in this way, say for example for a few minutes, the charcoal isplaced on the metal and stirred into it with a rod. It is preferable touse the old and partially burned charcoal which was used as a cover inmelting the metal. In other words it is preferable to use partiallyburned or calcined charcoal, or some carbonaceous material which has acomposition similar to partially burned or calcined charcoal. Thisheating and partial burning of the charcoal appears to drive off themoisture and gases from the charcoal. Also as the charcoal has beenpartially burned part of the carbon has been burned and it has arelatively high ash content. Its combustibility is therefore reduced andit is less active as a reducing agent thus permitting much more accuratecontrol of the deoxidizing operation and a more accurate determinationof the end point. A somewhat similar effect can be secured by calciningthe charcoal by roasting or by baking in an oven. If desired, thefurnace current may be applied at times to help this stirring operationand the deoxidizing of the copper by the charcoal. This operation ofstirring the charcoal into the molten copper is continued until allsigns of boiling in the copper have just disappeared. This is a definiteend point and shows that the copper has been brought to a condi- Thispoint is very definite and positive for a given temperature.

After this point is reached we add definite amounts of deoxidizer tocompletely deoxidize the copper, and as the oxygen content of the copperhas been, brought to a definiteamount we can, if desired, use just theamount of deoxidizer required so that only minute amounts of thedeoxidizers remain in the copper. The final deoxidizer or deoxidizersused are those which do not form a reaction product which is gaseous atroom temperature upon combining with the oxygen of the copper and aretherefore capable of preventing swelling of the metal'on freezing. Thisend point therefore gives us a definite condition from which the exactamount of deoxidizer required to give a complete deoxidation of thecopper can be definitely determined, and we can definitely determine theexact amount of deoxidizer required to give a complete deoxidation ofthe copper without a great surplus of deoxidizer remaining in thecopper, and we can therefore of course also definitely determine theexact amount of additional deoxidizer to add when we desire a givensurplus of deoxidizer in the copper as desired for forming certainalloys. The exact amount of deoxidizer required to be added after thisend point is reached is determined by testing. If after addof themanganese content in the copper.

ing some deoxidizer it is insufficient in amount a bar cast from thismetal will swell on freezing and will be unsound. If more deoxidizer isadded than is required to deoxidize the copper the electricalconductivity would be under 99.5 percent.

Therefore by observing the behavior of the metal on freezing and makingthe conductivity test the amount of deoxidizer required will be readilydetermined. These tests can be made for each deoxidizer it is desired touse, and after once determined for each deoxidizer can be depended uponto give uniform results. We have found that our end point is verydefinite and by introducing definite amounts of deoxidizer after the endpoint was reached our metal invariably met the conductivity and hydrogentests. Therefore when this definite end point is reached we add thedeoxidizer. If a metallic deoxidizer is used such for example asaluminum, this may be added either as metallic aluminum in small pieces,or, in order to secure very fine control of the aluminum content, it maybe added in the form of a copper aluminum alloy. Such alloy may containfor example 75 percent copper, and 25 percent aluminum, or any otherknown proportion may be used without affecting the principle ofoperation. It is also possible to use other metals than aluminum as thedeoxidizers, such for example as lithium, manganese, calcium, or anyother suitable metallic or non-metallic deoxidizer such as boron,phosphorus, and silicon, or such deoxidizers as calcium-boride, metallicphosphides metallic silicides, or other suitable deoxidizers as pointedout in the procedures above described. If sufficient of the deoxidizeris used to provide a surplus in the copper the deoxidizer chosen willdepend on the alloy which it is desired to produce as the final product.

We are not confined of course to the-use of a single deoxidizer as wemay use combinations of different deoxidizers or we may partiallydeoxidize with one deoxidizer and complete the deoxidation with anotherdeoxidizer. Thus for example we may partially deoxidize the copper withaluminum and then complete the deoxidation by the addition of manganese,preferably in the form of an alloy of copper and manganese as this willpermit a more delicate regulation or adjustment The other alloyingelement or elements may then be added to c mplete the alloy desired andthe molten met I poured into suitable molds and worked and used for thepurpose intended.

As a definite example of this method and operation 645 pounds of N. E.C. ingot copper (comprising approximately 99.9 percent pure copper) weremelted under a heavy layer of charcoal in a high frequencyelectric-furnace. The charcoal was used very freely as the copper wasmelted down, no attempt being made to use the charcoal sparingly. Thismelting operation usually requires about 1 hour and 25 minutes,although, of course, variations from this time are to be expected.

When the copper was melted and the proper heat attained, which weestimate to be in the neighborhood of 1200 C.,' the charcoal wascompletely skimmed off. The current may then again be applied, and theapplication of the current agitates the copper, and in the absence ofthe cover probably most of the contained gases are driven off orremoved, or at least the greater proportion of the easily oxidizablegases are oxiclized out. Also some oxidation of the .copper takesplaceas the copper is exposed to the air.-

This will oxidize the copper to a degree to give an oxygen contentconsiderably greater than the minute amounts which may already be in thecopper but it is never more than 0.090 percent and generally very muchless than this, probably less than 0.025 percent. From the time thecharcoal is removed until the current is again shut off there is a timeinterval of only a few minutes. During this time the metal may also, ifdesired, be stirred with a graphite or other suitable rod. At the end ofthis period the copper is somewhat active and has'the appearance ofboiling. After this stirring and agitating period is over some of theold or partially burned charcoal, which had previously been removed, wasplaced on the copper and the copper stirred rather vigorously with agraphite rod to stir in this charcoal. The partially burned or calcinedcharcoal is preferred as it permits more definite and delicate controlof the operation. After stirring in this charcoal for a minute or twothe current may again be placed on the furnace and allowed to run for ashort time. The copper is then inspected very carefully both in themiddle of its top surface and around its edges next to the container tosee if it is quiet or still agitated, or that is, has a boilingappearance. If the metal is not quiet this indicates that the end pointhas not been reached, and more charcoal is stirred in and the currentplaced on the furnace for a short time. The metal is then againinspected and if not quiet these operations are continued until themetal is quiet both around the sides of the top surface and in thecenter. This is a very definite end point and indicates that thedeoxidation by means of charcoal has been carried to a definite point,and therefore this end point is very fine and positive and indicatesthat the copper has been brought to a condition of definite oxygencontent, which is to the best of our knowledge less than 0.015 percent.This end point therefore gives us a definite and positive condition ofthe copper from which the the exact amount of deoxidizer required tocompletely deoxidize the copper may be determined. This end point alsoindicates the proper time for adding this deoxidizer.

If the copper was melted under oxidizing conditions, or that is, withoutthe cover, it is treated with charcoal and then the greater proportionof the gases allowed to escape before the partially burned or calcinedcharcoal is stirred into the metal. As the charcoal is stirred into themetal it may cause a boiling action due to the escape of the gasesformed by combining of the carbon of the charcoal with the oxygen of thecopper. The charcoal is stirred in until the boiling action ceases andthe metal becomes quiet, that is, until there is no more boiling action.This also gives the definite end point of definite oxygen content fromwhich the final deoxidizer may be added as above described. Also, asindicated above, after the proper and desired amount of the finaldeoxidizer has been added the desired amount or amounts of one or morealloying elements may be added to the copper to produce the desiredalloy the same as in the procedures described above.

We have discovered and worked out still an-' other procedure which maybe used for producing our improved alloy with deoxidized copper. It is amodified procedure employing certain treatments to bring the copper to adefinite end point or condition where it has a definite oxygen content,and we therefore can determine the exact amount of the deoxidizer whichshould be added to the copper before adding the .final alloyingelementor elements to secure the desired results and produce a uniformproduct having the characteristics desired. With this method we candetermine the exact amount of the deoxidizer which should be added todeoxidize the copper and still have a minimum amount of the deoxidizerremain in the copper, and we therefore can also accurately determine howmuch additional deoxidizer to add to secure a desired amount of residualdeoxidizer in the copper for any particular alloy we wish to produce.

In carrying out our method the copper may first be melted in anysuitable furnace, but we prefer the electric furnace known in the tradeas an induction furnace as the operations can more easily be controlled.However, we are not limited to the use of such furnace but may use othertypes of furnaces for melting the copper, such for example as what isknown in the trade as the high frequency furnace. The latter or highfrequency furnace is preferred for use in our procedure above describedwhere an end point is used which is indicated by the metal becomingquiet as the result of stirring in charcoal after boiling when exposedto the air.

In our present method or procedure the copper is preferably melted underreducing conditions and preferably under a cover of charcoal, but othercovers may be used. We prefer the charcoal as this gives us less workand more definite control in another part of the method.

When the copper is melted and a suitable temperature attained,preferably a temperature sultable for pouring, which is in theneighborhood of 1200 C., the charcoal or other cover is removed. Thecopper at this point contains gas, and if oxygen is present it is onlyin minute amounts. The copper may be melted without-the cover but inthis case after melting it should be subjected to reducing conditionsuntil it is substantially deoxidized. After the charcoal is removed wemay place electric current on the furnace and stir with a graphite orother suitable rod and expose the copper to the air in this way. Thisstirring action while exposed to the air removes most of the gas fromthe copper, although it is not necessary to remove all of it. As thecopper was melted under reducing conditions, although it may containgases the oxygen content, if any, is very small. It will therefore beevident that if we expose the copper to the air after removing thecharcoal cover for a given definite time this exposure and stirringaction removes gas from the copper or allows it to escape, probably mostof the gas in the copper, and the copper is brought to a definite oxygencontent or end point by partial oxidation of the copper, and ifsuccessive charges of approximately the same weight of copper areexposed for the same length of time they will be brought to this sameend point or condition. During this time the copper may or may not bestirred continuously, and the "current may or may not been the furnaceall of the time. At the end of this definite period of time asdescribedthe old or partially burned charcoal used as a cover in melting thecopper down, or other carbon in a form having a similar composition topartially burned or calcined charcoal, is placed on the copper and isthen stirred into the copper for a definite length of time. The currentmay be on for all or for a part only of this last stirringperiod oroperation. At the end of this last stirring period we add the finaldeoxidizer the same as in the procedures above described to deoxidizethe copper. We may use a metal for deoxidizing the copper, such forexample as aluminum, manganese, calcium, lithium, and other deoxidizers,or we may use non-metallic deoxidizers, such for example as boron,phosphorus, silicon, or we may use metallic borides, metallic silicides,metallic phosphides, or we may use two or more ofithese deoxidizersdepending on the final alloy which it is desired to produce. At the endof this second definite stirring period the copper has a definite oxygencontent and the amount of deoxidizer required to completely deoxidizethe copper or to produce a finished metal having given characteristicscan readily be determined. If it is desired that only a minimum of thedeoxidizer remain in the copper only sufiicient of the deoxidizer isadded to completely deoxidize the copper, while'if it is desired that asurplus or a residual amount of the deoxidizer remain in the copper,such for example as in using phosphorus preparatory to making aphosphor-bronze, then the amount of additional deoxidizer that may beadded to produce this surplus may be accurately determined. The endpoint at the end of the definite stirring time with charcoal gives us adefinite condition from which the exact amount of deoxidizer required,depending upon the characteristics desired in the finished alloy, can bedefinitely determined, although it is not necessary to know what theoxygen content is at this point.

The exact amount of deoxidizer to be added after this end point isreached or at the end of this definite period is determined by testing.If after adding some deoxidizer it is insufiicient in amount a bar castfrom this metal will swell on freezing and will be unsound. If more thanthe necessary amount of deoxidizer is added to com- .pletely deoxidizethe copper the electrical conductivity will be below 99.5 per cent at 20C. in terms of the International Annealed Copper Standard. Thereforeupon observing the behavior of the metal on freezing and making theconductivity test the amount of deoxidizer required can be readilydetermined. These tests can be made for each deoxidizer it is desired touse, and after once determined for each deoxidizer and for the twodefinite periods of exposure to the air and stirring in of the charcoal,

can be depended upon to give uniform results if the same conditions areobserved in treating subsequent charges of copper. We find that this endpoint is very definite andby introducing definite amounts of deoxidizerafter the end point is reached for these conditions our finished metalinvariably has the same characteristics.

' As in the other procedures described the final deoxidizer, such forexample as metallic aluminum, may be added either as a metallic aluminumin small pieces or in order to secure very fine control of the aluminumit may be added in the form of a copper-aluminum alloy. Whatever thedeoxidizer or deoxidizers used they may be the same and added in thesame manner as described in connection with the other procedures abovenoted and then one or more alloying elements may be added to thedeoxidized copper to produce the final alloys as above described.

Asa definite example of this method 645 pounds of N. E. C. ingot copperwere melted under a heavy layer of charcoal in an electric inductionfurnace.

ing operation usually requires about 1 hour and 25 minutes, although, ofcourse, variations of this time are to be expected.

When the copper was melted and the proper heat attained, which weestimate to be in the neighborhood of 1200 C., the charcoal wascompletely skimmed off. After skimming the charcoal the current wasapplied, and during this time the copper may be stirred with a graphiterod or other suitable rod. The application of the current agitates thecopper considerably which is also assisted by stirring with the rod, andin the absence of the cover probably most of the contained gases aredriven off or removed, and as the copper is exposed to the air someoxidation of the copper takes place. In the present example thisexposure to the air was for a definite period of time, in the presentcase three minutes, although this time may be varied as will bepresently indicated. During this time the copper may or may not bestirred continuously and the current may or may not be on the furnaceall of the time. This exposure to the air will oxidize the copper to adegree to give an oxygen content greater than the minute amounts whichmay already be in the copper. After exposure for the above length oftime the oxygen content was less than 0.025 percent.

At the end of this three minute period the partially burned charcoalused in melting the copper down was again placed on the copper and thischarcoal was stirred into the metal for a. definite period, in thepresent example for two minutes. No attempt was made to weigh or use apredetermined amount of carbon in the form of partially burned charcoal.We merely shoveled partially burned charcoal back on to the copperregardless of the amount of charcoal skimmed off before the stirring ofthe copper in contact with air. The electric current may be on thefurnace for all or a part only of this last stirring period as desired.This brings the metal to a definite end point or oxygen content and atthe end of this last stirring period we added the final deoxidizer. Asabove noted We may use one metal for deoxidizing the copper, such forexample as aluminum, manganese, or calcium, or we may use otherdeoxidizers as above described, or we may use two or more deoxidizersthe same as in the procedures above described.

, In the specific example above described we found that after stirringthe copper in the presence of air our oxygen content wasless than 0.025percent and that after the period of stirring the charcoal into thecopper the oxygen content was less than 0.01 percent. In other wordswhen the final deoxidizer was added there was less than 0.01 percentoxygen present in the copper. It will be evident that these amounts ofoxygen in the copper at the ends of the periods of the exposure to airand the stirring in of charcoal will vary depending on the length oftime of the periods, which may vary considerably as we re not limited tothe two and three minute periods given in the specific exampledescribed. It is preferred that the maximum content of oxygen be notover approximately 0.05 percent and probably would never go over, 0.09percent. Ordinarily it is not over 0.03 percent. Thus the lengths ofthese periods may be varied without affecting the final results, and forexample we might stir the copper for five, six or ten minutes when thecopper is exposed to the air and then stir with charcoal for a givensuitable length of time, which in this case would preferably be morethan the two minutes mentioned. We wish to point out .our methodinvolves the stirring of the copper when exposed to the air for adefinite length of time and then stirring in the presence of thecharcoal for a definite length of time, all before adding the finaldeoxidizer. By following this method a definite oxygen content isattained and the final deoxidizer can be controlled very nicely. Thus ifit is determined that with stirring for a given length of time incontact with air and stirring in contact with charcoal for a givendefinite time prior to adding the given amount of deoxidizer secures thedesired results, if successive charges of copper are stirred for thesame lengths of time in contact with air and in contact with charcoaland the same amount of the deoxidizer added, and then one or morealloying elements are added depending upon the alloy to be produced,metal will be secured having the same characteristics as the firstcharge. Although for certain results we prefer to start with copper of apurity of 99.5 percent or better, it is not required that we use highpurity copper.

Thus with the above described methods and procedures we have found wecan produce in commercial quantities alloys of uniformcharacteristics-and we can definitely produce alloys having thesecharacteristics and repeat as often as desired. This is possible becauseby these meth-' ods before adding the final deoxidizer the melted copperis brought to a definite point having a definite condition, or that is adefinite oxygen content, and this condition is, the same for separatecharges of copper which are treated in the same manner, and we havefound that by these methods improved alloys may be readily produced inlarge quantities and with uniformity in the mill.

We wish it distinctly understood that while describing the difierentprocedures above of making alloys we have referred to melting copper,permitting the gases to escape, deoxidizing, and so forth, we are notlimited to the use of new copper or copper alone. We have used the termcopper in describing the charge for simplicity and convenience, andalthough the charge may be entirely of new copper, ordinarily itcontains some scrap and mayeven be all scrap. In the manufacture and useof alloys there is always some scrap which must be used in subsequentcharges. Thus for example in making phosphor bronze as described above,we use a certain percent of phosphor bronze scrap and melt this scrapdown with the'copper. After the gases have been allowed to escape by oneof the methods described-we then treat the metal by any of theprocedures above outlined. In other words we have used the term copperin the specification and claims in a generic sense as describing acharge which may be all copper, or copper plus some scrap, or even allscrap if desired. The final steps would be to deoxidize the metal andadd an alloying element or elements as .described.

Having thus set forth the nature of our invention, what we claim is:

1. A method of making copper alloys comprising melting copper underreducing conditions, exposing the melted copper to air to permit escapeof gases and to partially oxidize the copper but to an oxygen contentless than 0.090 percent, adding non-carbonaceous deoxidizer which doesnot form a reaction product which is gaseous at room temperature uponcombining with the oxygen of the copper and sufilcient amount todeoxidize the copper, and then adding one or more alloying elements.

2. A method of making copper alloys comprising melting copper underreducing conditions, exposing the melted copper to the air to permiteasily oxidizable gases to escape, adding deoxidizer which does not forma reaction product which is gaseous at room temperature upon combiningwith the oxygen of the copper and suflicient in amount to deoxidize thecopper, and then adding one or-more alloying elements.

3. A method of making copper alloys comprising melting the copper undercharcoal, removing the charcoal and exposing the melted copper to theair to permit easily oxidizable gases to escape and partial oxidation ofthe copper not in excess of 0.090 percent oxygen, adding deoxidizerwhich does not form a reaction product which is gaseous at roomtemperatureupon combining with the oxygen of the copper and sufiicientin amount to deoxidize the copper, and then adding one or more alloyingelements.

4. A method of making copper alloys comprising melting copper underreducing conditions, exposing the melted copper to the air to permiteasily oxidizable gases to escape, adding deoxidizer which does not forma reaction product which is gaseous at room temperature upon combiningwith the oxygen of the copper and in excess of the amount required todeoxidize the copper, and then adding one or more alloying elements.

5. A method of making copper alloys comprising melting copper underreducing conditions, agitating the copper under oxidizing conditionsuntil it shows a boiling action, stirring carbonaceous material similarin composition to partly burned or calcined charcoal into the copperuntil the metal becomes quiet, adding deoxidizer which does not form a.reaction product which is gaseous at room temperature upon combiningwith the oxygen of the copper and at least sufii cient in amount todeoxidize the copper, and then adding one or more allowing elements.

6. A method of making copper alloys comprising melting copper underreducing conditions, agitating the melted copper under oxidizingconditions until it shows a boiling action, stirring partly burned orcalcined charcoal into the metal until it becomes quiet, then addingdeoxidizerwhich does not form a reaction product which is gaseous atroom temperature upon combining with the oxygen of the copper and atleast sufficient in amount to deoxidize the copper, and then adding oneor more alloying elements.

'7. A method of makingcopper alloys comprising melting the copper andexposing to reducing conditions for a suflicient time to substantiallydeoxide the copper, exposing the melted copper to the air until themetal becomes active by escape of gases, stirring carbonaceous materialsimilar in composition to partly burned or calcined charcoal into thecopper until it becomes quiet, adding deoxidizer which does not form areaction product which is gaseous at room temperature upon combiningwith the oxygen of the copper and at least sufiicient in amount todeoxidize the copper, and then adding one'or more alloying elements.

8. A method. of making copper alloys comprising melting copper undercharcoal, exposing the metal to the air until the metal becomes activeby escape of gases, stirring partly burned or calcined charcoal into theactive metal until it becomes quiet, adding deoxidizer which does-notloying elements.

tom a reaction product which is gaseous at room temperature uponcombining with the oxygen of the copper and at least sufllcient inamount to deoxidize the copper, and adding one or more al- 9. A methodof making deoxidized copper comprising melting the copper and treatingwith carbonaceous material to bring it to an oxygen content of less than0.090%, then exposing to the air to permit gases to escape and partialoxidation of the copper not in excess of 0.090% oxygen, and addingdeoxidizer which does not form a reaction product which is gaseous atroom temperature upon combining with the oxygen of the copper andsufficient in amount to deoxidize the copper.

10. A method of making deoxidized copper comprising melting the copperand subjecting to reducing conditions until it is substantiallydeoxidized, exposing the copper to the air to permit gases to escape andpartial oxidation of the copper not in excess of 0.090% oxygen, andadding deoxidizer which does not form a reaction product which isgaseous at room temperature upon combining with'the oxygen of the copperand sufficient in amount to deoxidize the copper.

11. A method of making deoxidized copper comprising melting copper underreducing conditions, exposing the melted copper to air to permit escapeof gases'and to partially oxidize the copper but to an oxygen contentless than 0.090%, and adding non-carbonaceous deoxidizer which does notform a reaction product which is gaseous at room temperature uponcombining with the oxygen of the copper and sufficient in amount toproduce a residual amount of the deoxidizer in the copper.

12. A method of making deoxidized copper comprising melting copper andsubjecting to reducing conditions, exposing the melted copper to air topermit gases to escape and oxidizing to a content of less than 0.090%oxygen, then adding deoxidizer which does not form a reaction productwhich is gaseous at room temperature upon combining with the oxygen ofthe copper and sufllcient in amount to deoxidize the copper.

13. A method of making deoxidized copper comprising melting the copperand subjecting to reducing conditions for a suflicient time to bring itto an oxygen content of less than 0.09%, ex-

posing the melted copper to the air to permit gases to escape andoxidation to an oxygen content of not more than 0.09%, and addingmetallic deoxidizer in excess of the amount required to deoxidize thecopper.

14. A method of making deoxidized copper comprising melting the copperunder reducing conditions, exposing the melted copper to the air topermit easily oxidizable gases to escape, and adding metallic deoxidizerin excess of the amount required to deoxidize the copper.

15. A method of. deoxidizing copper compris- "ing melting copper underreducing conditions and exposing the melted copper to air to permiteasily oxidizable gases to escape and a partial oxidation of the coppernot in excess of 0.090% oxygen, and adding metallic deoxidizer in excessof the amount required to deoxidize the copper.

16. A method of deoxidizing copper comprising melting the copper undercharcoal, removing the charcoal and exposing the melted copper to theair to permit easily oxidizable gases to escape and partial oxidation ofthe copper not in excess of 0.090% oxygen, and adding deoxidizer whichdoes not form a reaction product which is gaseous at room temperatureupon combining with the oxygen of the copper and suflicient in amount todeoxidize the copper.

1'7. A method of deoxidizing copper comprising melting the copper undercharcoal, removing the charcoah and exposing themelted copper to the airto permit easily oxidizable gases to escape and partial oxidation of thecopper not in excess of 0.090% oxygen, and adding metallic deoxidizer inexcess of the amount required to deoxidize the copper.

18. A method of making deoxidized copper comprising melting copper underreducing conditions, agitating the melted copper under oxidizingconditions until it shows a boiling action, stirring carbonaceousmaterial similar in composition to partly burned or calcined charcoalinto the copper until the metal becomes quiet, and adding deoxidizerwhich does not form a reaction product which is gaseous at roomtemperature upon combining with the oxygen of the copper and sufficientin amount to deoxidize the copper.

19. A method of making deoxidized copper comprising melting the copperunder reducing conditions, exposing the melted copper to the air andagitating until it shows a boiling action, treating with carbonaceousmaterial similar in composition to partly burned or calcined charcoaluntil the metal becomes quiet, and then deoxidizing by addingnon-carbonaceous deoxidizer which does not form a reaction product whichis gaseous at room temperature upon combining with the oxygen of thecopper.

.20. .A method of making deoxidized copper comprising melting copperunder reducing con-.

ditions, agitating the melted copper under oxidizing conditions until itshows a boiling action, stirring partly burned or calcined charcoal intothe metal until it becomes quiet, and then adding sufficient metallicdeoxidizer to prevent swelling of the metal on cooling.

21. A method of making deoxidized copper comprising melting the copperunder charcoal, exposing the copper to the air and at the same timeagitating it until it shows a boiling action,

then stirring partly burned or calcined charcoal into the metal until itbecomes quiet, and adding suflicient metallic deoxidizer to preventswelling of the metal on cooling.

22. A method of making deoxidized copper comprising melting the copperand bringing it to a substantially deoxidized condition, oxidizing thecopper sufliciently to cause a boiling action in the copper, stirringcarbonaceous material similar in composition to partially burned orcalcined charcoal into the copper until it becomes quiet, and thenadding deoxidizer which does not form a reaction product which isgaseous at room temperature upon combining with the oxygen of the copperand suflicient in amount to deoxidize the copper.

23. A method of making deoxidized copper comprising stirring acarbonaceous material similar in composition to partly burned orcalcined charcoal into partially oxidized melted copper until the copperbecomes quiet, and then deoxidizing the copper with a metallic reducingagent.

24. A method of making deoxidized copper comprising melting copper in asuitable container and exposing it to the atmosphere until the metalbecomes active by escape of gases, stirring partly burned or calcinedcharcoal into the metal until it becomes quiet, and then addingdeoxidizer which does not form a reaction product which is gaseous atroom temperature upon combining with the oxygen of the copper andsufiicient in amount to deoxidize the copper.

25. A method of making deoxidized copper comprising melting the copperunder charcoal, exposing the metal to the air until the metal becomesactive by escape of gases, stirring partly burned or calcined charcoalinto the active metal until it becomes quiet, and then adding sufiicientmetallic deoxidizer to prevent swelling of the copper on cooling.

26. A method of making deoxidized copper comprising melting the copperandgexposing to reducing conditions for a suflicient time tosubstantially deoxidize the copper, exposing the melted copper to theair until the metal becomes active by escape of gases, stirringcarbonaceous material similar in composition to partly burned orcalcined charcoal into the copper until it becomes quiet, and thendeoxidizing the copper by adding a sufficient amount of non-carbonaceousdeoxidizer which does not form a reaction product which is gaseous atroom temperature upon combining with the oxygen of the copper.

27. A method of making deoxidized copper comprising melting the copper,agitating the melted copper while exposed to the air to permit escape ofgases, stirring partially burned or calcined charcoal into the copperuntil signs of activity in the copper have disappeared,'and then addingsufllcient metallic deoxidizer to prevent swelling of the metal oncooling.

28. A method of making deoxidized copper comprising melting the copper,agitating the copper while exposed to the air to permit escape of gases,stirringpartially burned or calcined charcoal into the metal until signsof activity in the metal have disappeared, adding suflicient amount ofmetallic deoxidizer other than manganese to partially deoxidize thecopper, and adding a sufiicient amount of manganese to prevent swellingof the metal on cooling.

29. A method of making deoxidized copper comprising melting copper underreducing conditions, agitating the melted copper under oxidizingconditions until it shows a boiling action, stirring carbonaceousmaterial similar in composition to partly burned or calcined charcoalinto the copper until the metal becomes quiet, adding suflicient ofmetallic deoxidizer other than manganese to partially deoxidize thecopper, and then adding sufficient manganese to prevent swelling of themetal on cooling.

30. A method of making deoxidized copper comprising melting the copperunder charcoal, exposing the metal to the air until the metal becomesactive by escape of gases, stirring partly burned or calcined charcoalinto the active metal until it becomes quiet, adding sufiicient ofmetallic deox izer other than manganese to partially deoxidize thecopper, and then adding a suflicient amount of manganese to completelydeoxidize the copper.

31. A method of making deoxidized copper comprising stirringcarbonaceous material similar in composition to partly burned orcalcined charcoal into partially oxidized melted copper until the copperbecomes quiet, and then adding deoxidizer which does not form a reactionproduct which is gaseous at room temperature upon combining with theoxygen of the copper and sufliclent in amount to deoxidize the copper.

32. A method of making deoxidized copper comprising melting the copper,exposing the melted cOpDer to the air to permit escape of gases,stirring partially burned or calcined charcoal into the copper untilsigns of activity in the copper have disappeared, and then addingdeoxidizer which does not form a reaction product which is gaseous atroom temperature upon combining with the oxygen of the copper andsuflicient in amount to deoxidize the copper.

33. A method of making deoxidized copper comprising melting the copperunder reducing conditions, exposing the copper to the air to permitgases to escape, stirring carbonaceous material similar in compositionto partly burned or calcined charcoal into the copper for a period oftime sufficient to reduce the oxygen content of the melt to a definiteamount, and then adding deoxidizer which does not form a reactionproduct which is gaseous at room temperature upon combining with theoxygen of the copper and sufiicient in amount to deoxidize the copper.

34. A method of making deoxidized copper comprising melting the copperunder reducing conditions, agitating the melted copper under oxidizingconditions to permit gases to escape, stir ring partially burned orcalcined charcoal into the copper for a period of time suflicient toreduce the oxygen content of the melt to a definite amount, and thenadding deoxidizer which does not form a reaction product which isgaseous at room temperature upon combining with the oxygen of the copperand sufficient in amount to deoxidize the copper.

35. In the art of making deoxidized copper the method comprising meltingthe copper under reducing conditions, exposing the copper to the air andagitating to permit gases to escape, and stirring partially burned orcalcined charcoal into the copper for a period of time sufiicient toreduce the oxygen content to a definite amount.

36. In the art of making deoxidized copper, the method which comprisesmelting copper under reducing conditions, agitating the copper underoxidizing conditions until it shows a boiling action, and deoxidizingthe copper by stirring in partly burned or' calcined charcoal.

37. In the art of making deoxidized copper, the method which comprisesmelting copper under charcoal, exposing the copper to the air andagitating to permit gases to escape, and stirring partly burned orcalcined charcoal into the copper to deoxidize it.

38. In the art of making deoxidized copper, the

method which comprises melting copper under reducing conditions,exposing the melted copper to oxidizing conditions and agitating topermit gases to escape, and then stirring carbonaceous material similarin compositionto partly burned or calcined charcoal into the copper todeoxidize it.

39. A method of making deoxidized copper comprising melting the copperand bringing it to a substantially deoxidized condition, exposing themelted copper to the air until the metal becomes active by escape ofgases, stirring carbonaceous material similar in composition to partlyburned or calcined charcoal into the metal for a period of timesufficient to reduce the oxygen content of the melt to a definiteamount, and then adding deoxidizer which does not form a gaseousreaction product upon combining with the oxygen of the copper which willremain in the metal on solidification thereof and suflicient in amountto deoxidize the copper.

40. A method of making deoxidized copper com.- prising melting the copprunder charcoal, ex-

posing the copper to the air and agitating to permit gases to escape,stirring partly burned or calcined charcoal into the metal for a periodof time sufflcient to reduce the oxygen content of the melt to adefinite amount, and then adding deoxidizer which does not form agaseous reaction product upon combining with the oxygen of the copperwhich will remain in the copper on solidification thereof and suflicientin amount to deoxidize the copper.

41. A method of making copper alloys comprising. melting copper andtreating with carbonaceous material to bring it to an oxygen content ofless than 0.090 percent, then exposing to the air to permit gases toescape and partial oxidation of the copper not in excess of 0.090percent oxygen, adding deoxidizer which does not form a reaction productwhich is gaseous at room temperature upon combining with the oxygen ofthe copper and suflicient in amount to deoxidize the copper, and thenadding the alloy metal or metalsi 42. A method of making copper alloyscomprising melting the copper and subjecting to reducing conditionsuntil it is substantially deoxidized, exposing the copper to the air topermit gases to escape and partial oxidization oi the copper not inexcess or 0.090% oxygen, adding deoxidizer which does not form areaction product which is gaseous at room temperature upon combiningwith the oxygen of the copper and sufflcient in amount to deoxidize thecopper, and then adding an alloying metal or metals.

43. A method of making copper alloys comprising melting copper andsubjecting to reducing conditions to bring it to an oxygen content ofless than 0.090%, exposing the melted copper to air to permit gases toescape and oxidizing to a content of less than 0.090% oxygen, addingdeoxidizer which does not form a reaction product which is gaseous atroom temperature upon combining with the oxygen of the copper and suI-flcient in amount to deoxidize the copper, and then adding one or morealloying elements.

44. A method of making copper alloys comprising melting the copper andsubjecting to reducing conditions for a sufilcient time tobring it to anoxygen content of less than 0.09%, exposing the melted copper to the airto permit gases to escape and oxidation to an oxygen content of not morethan 0.09%, adding metallic deoxidizer in excess of the amount requiredto deoxidize the copper, and then adding one or more alloying elements.

45. A method of making copper alloys comprising melting the copper underreducing conditions, exposing the melted copper to the air to permiteasily oxidizable gases to escape, adding metallic deoxidizer in excessof the amount required to deoxidize the copper, and then adding one ormore alloying elements.

46. A method of making copper alloys comprising melting the copper underreducing conditions, exposing the copper to the air to permit gases toescape, stirring carbonaceous material similar in composition to partlyburned or calcined charcoal into the copper for a period of timesufllcient to reduce the oxygen content of the melt to a definiteamount, then adding deoxidizer which does not form a reaction productwhich is gaseous at room temperature upon combining with the oxygen ofthe copper and sufilcient in amount to deoxidize the copper, and thenadding one or more alloying elements.

47. A method of making copper alloys comprising melting copper underreducing conditions, agitating the melted copper under oxidizingconditions until it shows a boiling action, stirring carbonaceousmaterial similar in composition to partly burned or calcined charcoalinto the copper until the metal becomes quiet, adding deoxidizer whichdoes not form a reaction product which is gaseous at room temperatureupon combining with the oxygen of the copper and sufficient in amount todeoxidize the copper, and then adding one or more alloying elements.

48. A method of making copper alloys comprising melting the copper underreducing conditions, exposing the melted copper to the air until itshows a boiling action, treating with carbonaceous material similar incomposition to partly burned or calcined charcoal until the metalbecomes quiet, then deoxidizing by adding non-carbonaceous deoxidizerwhich does not form a reaction product which is gaseous at roomtemperature upon combining with the oxygen of the copper, and thenadding one or more alloying elements.

, 49. A method of making copper alloys comprising melting the copperunder charcoal, exposing the copper to the air until it shows a boilingaction, then stirring partly burned or calcined charcoal into the metaluntil it becomes quiet, adding sumcient metallic deoxidizer to preventswelling of the metal on cooling, and then adding one or more alloyingelements.

50. In the art of making deoxidized copper the method comprising meltingthe copper and treating with carbonaceous material to bring it to anoxygen content of less than 0.090%, exposing the copper to the air topermit gases to escape, and deoxidizing the copper by stirring in partlyburned or calcined charcoal.

HERBERT C. JENNISON. RICHARD B. MONTGOMERY.

